1. Field of the Invention
The present invention relates to a vehicle and some of its parts and more particularly to a manned welding and inspection vehicle for moving through a large-diameter conduit or pipe to perform welding and inspection procedures on said pipes. The invention also includes the housing used for the vehicle and more particularly the structure of the housing for the purpose of creating a predetermined air flow around the vehicle for removing welding gas and for cooling the power source of the vehicle. Additionally, the invention relates to the driving mechanism including a clutch apparatus for the vehicle; the driving mechanism allows the application of sufficient power to cause movement of the vehicle and yet the mechanism is in an extremely compact package. Further, the invention relates to an adjustment mechanism for the welding head of the vehicle to provide versatility as well as superior welding results.
2. Description of the Prior Art
The current energy shortage as well as the ever-increasing use of natural resources have resulted in the need for the construction of long pipelines of large diameter. The best current example is commonly referred to as the "Alaskan Pipeline," a pipeline for the movement of oil from the Alaskan North Slope at Prudhoe Bay to the Southern Coast at Valdez, some 800 miles, for shipment by tankers. Other large pipelines are also being constructed or planned for oil as well as gas.
To date, much of the welding of pipeline is done manually. However, manual welding is expensive, time consuming, and results in inconsistent welding quality. Furthermore, in a hostile environment, such as that existing in Alaska, simply administering large groups of manual welders is extremely difficult and expensive.
Some automatic welding equipment has been developed, but to date their record is spotty. It is still difficult to get good quality welds and machinery failure is still common. Also, existing automatic welders are generally of the type which weld iron outside of the pipeline, while it is desirable to have an inside weld capability. Further, present pipeline welding procedure usually entails the digging of a ditch for the pipeline (where the pipeline is to be placed into or underground), placing the pipes immediately alongside the ditch, welding the pipes together and then lowering the pipes into the ditch. Because of the stresses induced in the pipes upon movement, it would, of course, be more desirable to perform at least some of the welding procedure after the pipes are in their permanent location.